Friction-clutch.



0. M. ALEXANDER.

FRICTION CLUTCH.

APPLICATION FILED DEC. 4. 1914.

1,139,Q4%9o Patented May11,1915.

i A easiest OLIN M. ALEXA 1\TDER, F ANNISTON, ALABAMA.

FRICTION-CLUTCH.

Specification of Letters Patent.

Patented May 11, 1915.

Application filed December 4, 1914. Serial No. 875,535..

To all whom it may concern:

Be it known that I, OLIN M. ALEXANDER,

a citizen of the United States, residing at Anniston, in the county of Calhoun and State of Alabama, have invented new and useful Improvements in Friction-Clutches, of which the following is a specification.

This invention relates to improvements in friction clutches, proposing a friction clutch which is especially designed asa part of a change speed gearing for transmitting power from one shaft to another, a specific application of the improved clutch being its use in automobile transmission gearing as a connecting element between the crank shaft or a shaft driven thereby and a shaft employed to drive the. wheels of the vehicle.

The objects of the invention are to provide a friction clutch of the character stated which permits of an easy and accurateregulation of the speed of the driven shaft and which is specially constructed whereby transmission from lower'to higher speeds shall be easy and gradual and without shock. v

Otherobjects and advantages will appear as the description proceeds.

' An embodiment of the invention is illustrated in the accompanying drawings, wherein V Figure 1 is a vertical longitudinal sec.- tional View of a friction clutch in which the features of the invention are incorporated; Fig. 2 is a horizontal sectional view thereof; Figs. 3 and 4 are; vertical cross sectional views showing different relations of the parts, Fig. 3 showing the driven member "substantially free of the driving member,

and Fig. 4 showing the said driven and driving members coupled together whereby the latter operates the former. Fig. 5 is a detail perspective view showing'the means ernployedfor expanding the inner member of the clutch.

Similar characters of reference designate corresponding parts throughout the several views.

. The two shafts vbetween which power is transmitted are indicated at 1 and 2 and it may assumedthat 1 is the driving shaft and 2-the, driven shaft. In the embodiment disclosed,.. these shafts are arranged in ooaxial oralining relation and are jpurnaled in thewalls of a casing 3 which ncloses the gearingof which the clutch forms a art,

and is suitabl seemed to the frame 1; the

engaging sections 7, each having a circumference of slightly less than half a circle and of a curvature conformable to that of the inner face of the ring 5. The clutch element 6 is mounted upon the inner end of the shaft 1 and its sections are actuated to operatively connect the shafts l and 2 by a wedge means preferably comprising wedge fingers 8 pro- Jecting from a collar 9. The shaft 1 is formed with opposite, preferably parallel, fiat faces 10 of suitable length, and the sections 7 are formed with longitudinal grooves 7 adjoining the faccslO. he wedge fingers 8 slide along the faces 10 and fit conformably in the grooves 7', thereby keying the member 6 to the shaft 1. The grooves 7 are preferably formed to exactly conform to the outline ofthe wedge fingers 8.

j The wedge fingers act in opposition to bow springs 11 each of which is of curved outline and has an extent approximating that of half a circle. are carried by the driving ring 5, their ends in transverse slits 12 which are formed in the inner circumferential face of said driving ring; and said bow springs are fitted in a circumferential groove 13 formed The bow springs 11 in the inner face of the driving ring 5 and in circumferential grooves 14 formed in the outer faces of the sections 7, being disposed partly in the groove 13 and partly in the grooves 14. The springs 11 tend to spring inwardly and thus to oppose the movement of the wedge fingers 8 in a direction to spread the sections 7.

The collar 9 is journaled in an operating sleeve 15 which is slidably mounted upon the shaft 1 and is preferably, though not necessarily, acted upon by a spring 16 which tends to move said sleeve toward the member 6. The sleeve 15 is, in turn, operated by a lever 17, the latter being pivoted at its lower or inner end to the sleeve 15 and above its pivotal connection with the sleeve 15,

a conventional pawl 20 for engagement with said quadrant.

When the sleeve 15 is positioned as far as possible from the member 6, the driving ring 5 will be practically free of said memher and the shaft 1 may, therefore, rotate, without producing any rotation of the shaft 2. In order to operate the shaft 2, the sleeve 15 is moved toward the member 6, such movement of the sleeve 15 producing an inward movement of the wedge fingers 8, and the latter spreading or expanding the sections 7, as is obvious. As the sections 7 are spread or expanded by the wedge fingers 8, their frictional engagement with the springs 11 becomes sufficiently strong to cause a rotation of the shaft 2 consequent to the rotation of the shaft 1. Obviously, the speed at which the shaft 2 rotates is proportionate to the degree of frictional engagement between the sections 7 and the springs 11, the speed of the shaft 2 being higher as the frictional engagement of the springs 11 and the sections 7 is greater, and being lower as the frictional engagement of the springs 11 and sections 7 is less. Thus, in one position of-the fingers 8 wherein said fingers will be substantially retractedfrom the member 6, the rotation of the shaft 1 will not produce any rotation of the shaft 2, but in the opposite extreme positions of the fingers 8 wherein said fingers are projected as far as possible into the member 6, the shaft 2 will rotate at a speed which is substantially equal to the speed of, the shaft 1, and in intermediate positions of thetingers 8 the shaft 2 will be rotated by the shaft 1 but will have less speed of rotation than the shaft 1, this difference between the speed of rotation of the shafts 1 and 2 being obviously due to the slippage of the member 6 relatively to the springs 11. The springs 11 are suiiiciently stout to have good wear-resisting properties and are sui'liciently long and wide to have ample frictional engaging surfaces. When the fingers 8 are retracted from the member 3 the springs ll, which, as

above stated, tend to spring inwardly, will obviously move the sections '2' toward one another, and as said sections are moved inwardly by the springs 11, theirdegree of frictional engagement with said springs will progressively decrease, as is obvious.

When the fingers 8 are projected as far as possible into the member 6 the shaft 2 will, as above stated, rotate at a speed which is substantially equal to the speed of the shaft 1. This is due, in the embodiment shown, not only to the fact that the springs 11, at such time, have their strongest fric tional engagement with the sections Y, but

' also to the fact that the circumferential faces of the sections 7 at the sides of the grooves 14 bear uniformly throughout their extent with strong frictional pressure messes against the inner circumferential faces of the ring 5 at the sides of the groove '12.

The springs 11 prevent the changes from lower to higher speeds from being made too suddenly or from being accompanied by undue shocks, and, on the other hand, where the speed is changed from higher to lower, by virtue of their engagement with the sections 7, exercise a braking function and thus counteract the momentum of the vehicle and insure that the shaft 2 shall be substantially as responsive to the gearing when the speed is changed from higher to lower asit is when the speed is changed from lower to higher.

The transverse grooves or .recesses 12 in which the ends of the springs 11 fitare arranged at such an angle or pitch as to insure that said springs shall form an eflicient driving connection between the member 6 and the driving ring 5 and have such depth as to allow of the requisite play of the ends of the springs as the tension of the latter is decreased or increased and thus to prevent the springs from buckling consequent to changes in their curvature.

Having fully described my invention, 1 claim 1. The combination of driving and driven co-acting clutch elements, one comprising a ring and the other comprising a radially expansible member mounted within the rin a shaft carrying the radially expansible member and having fiat longitudinal faces, and wedge fingers mounted to slide along said flat faces and operative to expand said radially expansible member.

2. The combination of driving and driven co-acting clutch elements, one comprising a ring and the other comprising a disk mounted within the ring and formed in sections, a shaft carr ing the disk and having fiat longitudinal faces, and wedge fingers mounted to slide along said fiat faces and operative to spread the sections of said dish.

8. The combination of driving and driven co-actin clutch elements, one comnrisinga ring an the other comprising a dish mounted within the ring and formed in sections, bow springs associated with one of said clutch elements and interposed between and cod forming to the outline of the adjacent circumferential cos of said ring and said dish, a shaft carr ing the dislr, and means for spreading or expanding the sections of the disk,

t. The combination of driving wd driven co-acting clutch elements, one comprising a ring and the other comprising a disk mounted within the ring and formed in sections, a shaft carrying the disk, the adjacent faces of the disk and the ring being circumferem tially grooved, bow springs associated with the ring and interposed in said circumferen tialgrooves and conforming to the outline thereof, and means for spreading or expand'ing the sections of the disk, the bow springs tending to spring inwardly.

5. The combination of driving and driven cowacting clutch elements, one comprising a ringand the other comprising a disk mounted within the rim and formed in sections, a shaft carrying t e disk, the adjacent faces of the disk and the ring being circumferentially grooved, bow springs interposed in said circumferential grooves and conforming to the outline thereof, the ring having its inner face provided with transverse grooves and the bow springs having their ends fitted in said transverse grooves, the

. bow springs tending to spring inwardly,

and means for spreading or expanding the sections of the disk.

6. The combination of driving and driven co-acting clutch elements, one comprising a ring and the other comprisin a disk mounted within the ring and formed in sections, bow springs associated with one of said clutch elements and interposed between longitudinal and conforming to the outline of the adjacent circumferential faces of said ring and said disk, a shaft carrying the disk and having flat longitudinal faces, and wedge fingers mounted to slide along said flat faces and operative to spread the sections of said disk.

7. The combination of driving and driven co-acting clutch elements, one comprising a my hand in presence. of two subscribing witnesses.

OLIN M. ALEXANDER. Witnesses:

A. A. BEAL, B. J. Aw'mr. 

